FIG. 13 illustrates an arrangement of a mobile communication system generally known in the art. This mobile communication system 1 is composed of a mobile station 10, base stations 20_1-20—n (hereinafter, occasionally represented by a base station 20) respectively communicating with the mobile station 10 through wireless lines RL1-RLn (hereinafter, occasionally represented by a wireless line RL) and network connecting devices 30_1-30—m connected to the base stations 20 with a wired line WL to relay signals between the base stations 20 and a communication network NW.
It is to be noted that in order to effectively use the wireless line RL with a restricted frequency band or the like, there is a method by which the mobile station 10 or the base stations 20 monitor a wireless line usage rate (using or use rate) indicating a usage status of the wireless lines.
Related art examples [1] and [2] for the monitoring technology will now be described referring to FIGS. 14-17: